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101.
Cortisol and finfish welfare 总被引：1，自引：0，他引：1
Ellis T Yildiz HY López-Olmeda J Spedicato MT Tort L Øverli Ø Martins CI 《Fish physiology and biochemistry》2012,38(1):163-188
Previous reviews of stress, and the stress hormone cortisol, in fish have focussed on physiology, due to interest in impacts
on aquaculture production. Here, we discuss cortisol in relation to fish welfare. Cortisol is a readily measured component
of the primary (neuroendocrine) stress response and is relevant to fish welfare as it affects physiological and brain functions
and modifies behaviour. However, we argue that cortisol has little value if welfare is viewed purely from a functional (or
behavioural) perspective—the cortisol response itself is a natural, adaptive response and is not predictive of coping as downstream
impacts on function and behaviour are dose-, time- and context-dependent and not predictable. Nevertheless, we argue that
welfare should be considered in terms of mental health and feelings, and that stress in relation to welfare should be viewed
as psychological, rather than physiological. We contend that cortisol can be used (with caution) as a tractable indicator
of how fish perceive (and feel about) their environment, psychological stress and feelings in fish. Cortisol responses are
directly triggered by the brain and fish studies do indicate cortisol responses to psychological stressors, i.e., those with
no direct physicochemical action. We discuss the practicalities of using cortisol to ask the fish themselves how they feel
about husbandry practices and the culture environment. Single time point measurements of cortisol are of little value in assessing
the stress level of fish as studies need to account for diurnal and seasonal variations, and environmental and genetic factors.
Areas in need of greater clarity for the use of cortisol as an indicator of fish feelings are the separation of (physiological)
stress from (psychological) distress, the separation of chronic stress from acclimation, and the interactions between feelings,
cortisol, mood and behaviour. 相似文献
102.
Conceição LE Aragão C Dias J Costas B Terova G Martins C Tort L 《Fish physiology and biochemistry》2012,38(1):119-141
Little research has been done in optimizing the nitrogenous fraction of the fish diets in order to minimize welfare problems.
The purpose of this review is to give an overview on how amino acid (AA) metabolism may be affected when fish are under stress
and the possible effects on fish welfare when sub-optimal dietary nitrogen formulations are used to feed fish. In addition,
it intends to evaluate the current possibilities, and future prospects, of using improved dietary nitrogen formulations to
help fish coping with predictable stressful periods. Both metabolomic and genomic evidence show that stressful husbandry conditions
affect AA metabolism in fish and may bring an increase in the requirement of indispensable AA. Supplementation in arginine
and leucine, but also eventually in lysine, methionine, threonine and glutamine, may have an important role in enhancing the
innate immune system. Tryptophan, as precursor for serotonin, modulates aggressive behaviour and feed intake in fish. Bioactive
peptides may bring important advances in immunocompetence, disease control and other aspects of welfare of cultured fish.
Fishmeal replacement may reduce immune competence, and the full nutritional potential of plant-protein ingredients is attained
only after the removal or inactivation of some antinutritional factors. This review shows that AA metabolism is affected when
fish are under stress, and this together with sub-optimal dietary nitrogen formulations may affect fish welfare. Furthermore,
improved dietary nitrogen formulations may help fish coping with predictable stressful events. 相似文献
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104.
Despite the fact that tree plantations are not able to completely replace the ecological function of natural forests, the present study proposes to evaluate for which bird species or avian groups tree plantations act as habitat in fragmented landscape in southern Brazil. We compared the richness and abundance of bird species in a natural forest to adjacent plantations of Araucaria, a native tree species and of pine, an exotic plant in South America. Moreover, we evaluated the impact of tree plantations on richness of avian groups with different levels of dependence on forest habitat, feeding habits and foraging strata as well as on threatened species. The fixed 100 m radius point-counts method was used. A total of 114 bird species were recorded in all areas. Of those, 93 occurred in natural forest, 87 in Araucaria plantations and 81 in pine plantations. These results indicate that richness and abundance were lower in the pine plantations than in the natural forest and in the Araucaria plantations. Araucaria plantations can be used by a high number of bird species and their richness was not significantly lower than that observed in the adjacent natural forest. Our results suggest that Araucaria plantations could act as habitat for a large number of bird species, especially for forest-dependents species, insectivores, frugivores and species at different threat categories. 相似文献
105.
Effects of insecticide Thiodan® on the morphology and quantification of ovarian follicles in lambaris Astyanax bimaculatus (Linnaeus, 1758) in different treatments 
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下载免费PDF全文 Lucas Marcon Ann Honor Mounteer Nilo Bazzoli Laércio dos Anjos Benjamin 《Aquaculture Research》2016,47(8):2407-2418
Thiodan® is an insecticide which can cause morphological changes in fish tissues, dependent on the concentration. To investigate possible morphological changes, this study evaluated the number and diameter of ovarian follicles in lambaris Astyanax bimaculatus exposed to Thiodan® for 96 h in different treatments at three sub‐lethal concentrations: 1.15, 2.3 and 5.6 μg L?1 and a control group without Thiodan®. Females exposed to Thiodan® were divided into four treatments: (i) without acclimation and without food, (ii) without acclimation and with food, (iii) with acclimation for 10 days and without food; (iv) with acclimation for 10 days and with food. In this study, it was noted that the action of Thiodan® at sub‐lethal concentrations in a static system did not affect the morphology of follicular development. However, the treatments with acclimation showed lower numbers of primary and secondary follicles when compared to fish from treatments without acclimation. For the groups exposed to Thiodan®, a greater number of atretic follicles were observed compared to the control groups. The follicular diameter of secondary follicles in fish exposed to Thiodan® in the treatment with acclimation and with food was highest in the control group (P < 0.05). Furthermore, the mean gonadosomatic (GSI) and hepatosomatic (HSI) indices of treatments with acclimation were lower than those for treatments without acclimation. These data suggest that the fish may be being affected by the pesticide to which the fish were submitted, and may cause impairment to the follicular development. 相似文献
106.
The health of 3081 heifer calves born in 122 dairy herds in the south-west of Sweden from 1 January to 31 December, 1998, was monitored from birth until 90 days of age. The calves were kept either in individual pens (n=2167), in group pens, with 3–8 calves to a pen and manual feeding of milk (n=440), in group pens with 6–30 calves per pen and an automatic milk-feeding system (n=431), or with their dams (n=43). Disease incidence was recorded by farmers and project veterinarians, who clinically examined the calves and auscultated their lungs every 2–3 months. A disease was graded as ‘severe’ if the general loss of condition or of appetite in the calf continued for >2 days or if the animal suffered severe weight loss due to the disease. The effects of season, breed, housing, and type of colostrum feeding, and time, place and supervision of calving on the incidences of diarrhea, severe diarrhea, respiratory disease, other infectious disease and moderately to severely increased respiratory sounds, were analyzed by logistic-regression models (with herd as a random effect). The total morbidity rate was 0.081 cases per calf-month at risk. Incidence rates of arthritis, diarrhea, omphalophlebitis, respiratory disease and ringworm were 0.002, 0.035, 0.005, 0.025 and 0.009 cases per calf-months at risk, respectively. The odds ratios for diarrhea and severe diarrhea were increased in Swedish Red and Whites (OR: 1.6, 2.3) and in calves that received colostrum from first-lactation cows (OR: 1.3–1.8), and for severe diarrhea in calves born in summer or that received colostrum through suckling (OR: 1.7, 1.8). The odds ratios for respiratory disease and increased respiratory sounds were increased in calves housed in large-group pens with an automatic milk-feeding system (OR: 2.2, 2.8). Supervision of calving was associated with a decreased odds ratio for respiratory disease (OR: 0.7) and birth in individual maternity pen or tie stalls with a decreased odds ratio for increased respiratory sounds (OR: 0.5–0.6). Cross-breeds with beef breeds were associated with increased odds ratios for increased respiratory sounds (OR: 2.1–4.3) and colostrum from second-lactation cows and birth during night for other infectious disease (OR: 1.6, 1.5). 相似文献
107.
Denner Santos dos Anjos Paula Barbosa Costa Larissa Fernandes Magalhães Oscar Rodrigo Sierra Sabryna Gouveia Calazans Carlos Eduardo Fonseca-Alves 《Topics in companion animal medicine》2018,33(3):73-76
A 12-year-old Rottweiler dog was presented with a history of prostration, weight loss and hyporexia for six months. Based on complete blood tests (hematological and biochemical analyses), bone marrow examination and imaging analysis, a diagnosis of chronic myeloid leukemia was made. Treatment with hydroxyurea at a dosage of 18?mg/kg twice daily was not effective in controlling the high count of white blood cells. Furthermore, after 35 days of hydroxyurea treatment, the animal developed onycholysis, with sloughing of the claws of the left pelvic and left thoracic limbs and exposure of the distal phalanx. Interruption of the medication was implemented, with clinical healing of the ungual lesions observed three months after initiation of the drug. White blood cells returned to normal after using cyclophosphamide. Currently, the animal is in complete remission, having a disease-free interval of 575 days without chemotherapy. To the authors' knowledge, this is the first report of hydroxyurea-induced onycholysis within a short-term period in a dog diagnosed with chronic myeloid leukemia. 相似文献
108.
Comparison of portuguese soils from different geographical regions using physicochemical,biological and biochemical parameters 总被引：1，自引：1，他引：0
109.
As a consequence of water re‐use and high stocking densities, Recirculating Aquaculture Systems (RAS) may lead to an accumulation of substances released by the fish into the water, e.g. cortisol and alarm pheromones. This study investigated the effect of stressing fish on the feeding motivation of other fish not subjected to stress but sharing the same water of stressed fish. Two identical RAS were used (operated at 30 L kg feed?1 day?1) and contained grouped (stressed fish) and individually (receiving water from stressed fish) housed Nile tilapia. A stress test was applied in grouped housed fish on days 17 and 55. Feeding behaviour (intake and latency) was recorded in the individually housed fish 3 days before, during and 3 days after the stress test. The results showed no effect on feeding behaviour in fish receiving the water from stressed fish. These results could be a consequence of insufficient cortisol/alarm cues' release by the stressed fish into the water or inactivity of such substances, either due to a trapping effect of humic acids or due to degradation in the nitrification and denitrification processes. Future research is needed to clarify how these processes may affect the water concentration of cortisol and alarm pheromones and should be extended by measuring other behavioural and physiological traits. 相似文献
110.